Recently, due to the remarkable development of information communication technology and semiconductor technology, the spread and use of mobile terminals are rapidly increasing. In particular, recent mobile terminals have branched out from their traditional areas, ushering in a mobile convergence era in which areas of other terminals are included through performance improvement.
Representatively, in addition to a general communication function such as voice calling or transmission and reception of messages, various functions such as a TV viewing function (for example, mobile broadcasting such as digital multimedia broadcasting (DMB) or digital video broadcasting (DVB)), a music reproducing function (for example, MPEG audio layer-3 (MP3)), a photographing function, and an Internet access function have been added to a mobile communication terminal.
Furthermore, as recent mobile communication terminals develop into the form of smartphones in which a user can arbitrarily install various user functions based on an open OS, convenience and varieties of entertainment have been provided. Such smartphones support customers in easily obtaining applications having various desired functions with activation of open markets. In addition, high-performance smart phones can process many functions processed in a PC.
Such convergence trends are spreading to other electronic devices in addition to mobile communication terminals. For example, open OSs are being installed in TVs, which have so far been operated as simple image receiving devices, causing convergence of communication functions enabling various services to be used as in a smartphone or a PC.
In this way, as various electronic and communication devices have similar functions, there is growing interest in a multi-device environment in which a service can be used through two or more different terminals at the same time.
In such a multi-device environment, the user can use the same service and function through various terminals such as a TV, a desktop computer, a laptop, a tablet PC, and a smartphone at the same time without being limited to a specific terminal.
In particular, in a message service that allows a text-based message to be exchanged between users, a service has been provided based on the multi-device environment in which a message related to the user is simultaneously provided to a plurality of terminals registered by the user, and thus the user may check a received message or transmit a message to another user through any terminal.
However, in such a multi-device environment in which a single user uses the plurality of terminals, there are problems and inconveniences that are difficult to predict based on an existing environment having a one-to-one correspondence between the user and the terminal.
For example, a privacy disclosure problem or a user presence information processing problem may occur when the message is simultaneously transmitted to a plurality of user terminals.